Apparatus for recovering soda



(N oModeL) I v 1 1, EMERSON. ,APPARATUS'FOR REGO VERING SODA; No. 377,551.. H Patented Feb. '7, 1888. 1

UNITED STATES PATENT OFFICE.

RUFUS H. EMERSON, OF JACKSON, MICHIGAN.

I APPARATUS FQR RECOVERING SODA.

SPECIFICATION forming part of Letters Patent No. 377.551, dated February 7,1888.

Application filed April 11, 1887. Serial No. 234.340. (No model.)

To all whom it may concern:

Be it known that I, BUFUs H. EMERSON, of the city of Jackson, in the county of Jackson and State of Michigan, have invented a new and useful Improvement in Apparatus for Hecovering So'da'in the Manufacture of Paper- Pulp, of which the following is a specification.

This invention relates to the recovery of soda from the spent liquor in the manufacture of paper stock or pulp by the treatment of vegetable fiber with a solution of caustic soda, and it has the object to utilize in an efficient mannerthe heat which is generated by incinergting the waste material in recovering the so a.

My invention consists of the improvement which will be hereinafter fully set forth, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a sectional elevation of an apparatus embodying my improvements. Fig. 2 is a sectional top plan view of the same. Fig. 3 is a crosssection showing a modified'const'ruction of the apparatus.

Like letters of reference refer to like parts in the several figures. V

A. represents an evaporating apparatus of any suitable or well-known construction, in which the spent liquor coming from the digester is evaporated and concentrated. A Vacuum apparatus such, for instance, as is described in Letters Patent No. 300,185, June 10, 1885-is preferably employed for this purpose. The spent liquor is introduced into the evaporator through a pipe, a, and the concentrated liquor is discharged through a pipe, b, into a receiver, B.

0 represents a steam-coil, arranged in the evaporator Afor heating its contents; but any other suitable steam-heating appliance-such, for instance, as a.heating-jacket-may be employed, if preferred. V

1) D represent the incinerating hearths, which receive the concentrated liquor from the receiver B by pipes d d.

' E E represent furnaces arranged at the front ends of the hearths, and e e represent the direct fiues,which extend from the furnaces over the hearths. I

f f represent the arches which cover the lines 6 e and separate the latter from the returnfiues g g,which are arranged above the arches,

flues, through which the gases pass from the front ends of the return-fines g to the chimney J k represent steam-pipes,which connect the boilers I I with the evaparator A and supply steam to the same for evaporating the spent liquor.

The spent liquor coming from the digester has a gravity of about 4 Baum, and is concentrated in the evaporator A to a gravity of about 32 Baum. This concentrated liquor is supplied to one of the hearths D, where itis still further concentrated to a gravity of about 40 Baum by means of a fire started in the connecting furnace E. When the liquor reaches a high gravity,itassumes a pasty consistency andbecomes ignited and burns fiercely. The fire in the furnace is now permitted to go down and the steam is generated in the boiler surmounting the hearth by the heat derived from the burning material on the hearth. Be-

fore the incineration begins the steamboileris heated by means of the furnace E, which is fired for the double purpose of concentrating the material on the hearth to the point of ignition and heating the steam-boiler above the hearth. I prefer to use two sets of hearths, furnaces, and boilers, so that one hearth can be charged with fresh liquor and made ready for incineration while the incineration proceeds on the other hearth, thereby generating steam of the required temperature in one or the other boiler for supplying the evaporator. By thus employing the waste heat of the incinerating process ingenerating steam a large percentage of said heat is absorbed or utilized in making steam and enabled to be used for evaporating the spent liquor or for other purposes in such quantities and at such distances from the incinerating-hearths as circumstances may require.

' If preferred, one steam-boiler may be em-' ployed in connection with two hearths, as indicated in Fig. 3, in which the direct flues extending over the hearths are connectedwith a single return-flue under the boiler by passages flue over the hearth which is cold can be'separated from the flue under the boiler by shutnace over said hearth, a steam-boiler having ting the damper. its flue connected with the exitflue of the I claim as my invention hearth, and an evaporator connected with said 1. The combination, with an incineratingsteam-boiler, substantially as set forth. 1

5 hearth, of a steam-boiler heated by the waste Witness my hand this 28th day of March,

heat from said hearth, and an evaporator 1887. heated b5 steam from said boiler, substantially as set forth.

2. The combination, with an incinerating- Witnesses: 1o hearth, of'a furnace arranged at one end of a i G. H. BENNETT, said hearth, a flue extending from said fur- SAiML. H. CAMP.

RUFUS H. EMERSON. 

